XOM API for Processing XML with Java

[Elliotte Harold <elharo AT metalab.unc.edu>]

Michael Kay wrote:

> > Elliotte Harold scripsit:
> >
> >
> > > What XPath 1.0 expressions might you use 
> > > in a Java program that do not return node-sets?
> >
> > I can't think of any.
>
>
> I think you're assuming a scenario where users like to code in Java and only
> use XPath as a last resort. There's another scenario where users hate coding
> in Java (all those fiddly iterators) and like to use XPath as much as
> possible. 

I think that's accurate. I assume such users will use XSLT or XQuery 
rather than Java+XOM. I hear a lot more pain from Java programmers who 
can't get a handle on XSLT than from XSLT programmers who can't get a 
handle on Java.

> There's also a scenario where the Java application with embedded
> XPath is machine-generated.
>
> sum(*[@code=23]/@value)
> lang('de')
> count(../following-sibling::foo) = 0

That's an interesting use case. It's not one I've encountered before. 
Can you provide some more information about such machines? i.e. is there 
anywhere I can look at some such software to see what they're doing, 
what their needs are, how useful they are, and so forth? Personally, I 
don't think I've ever written software that generated XPaths.

 I was thinking about this yesterday when I noticed dom4j had a 
function to generate a location path for any given node. I've seen 
several people ask for this in various contexts, and I thought I might 
write a sample program that did this, though I wasn't going to add it to 
the core like dom4j did. However, that expression always returns a 
node-set; and it's the only example of machine generated XPath I can 
think of right now.

--
Elliotte Rusty Harold  elharo AT metalab.unc.edu
XML in a Nutshell 3rd Edition Just Published!
http://www.cafeconleche.org/books/xian3/
http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim